Mechanical movement



Sept. 19, 1944'. ROBBINS 2,358,595

MECHANICAL MOVEMENT Filed April is, 1943 ZSheetS-Sheet 1 11v TOR. I ELEO ROB N5 N 7 5 BY 42 jl WM W; HTTORNEY Sept. 19, 1944.

L. ROBBINS.

MECHANICAL MOVEMENT' Filed April 15, 1943 2 Sheets-Sheet 2 INVENTOR.

- L 50 ROBBINS Patented Sept. 19, 1944 UNITED STATES PATENT OFFICE,

MEOHANICAL MOVEMENT Leo Robbins, New York, N. Y., assignor to RobertsManufacturing 00., New York, N. Y.

Application April 15, 1943, Serial No. 483,091

9 Claims.

This invention relates to a mechanical movement, and has foritsprincipal object the provision of means for amplifying or multipyingthe movement of a member. Moreparticularly, this movement relates tothat type of apparatus in which acam operates a follower to rotate agear or other member through an angular distance. The limitations whichare inherent in such a system are well known, and consists principallyin the fact that a cam cannot be employed forangular movement of afollower in excess of 90, which is the theoretical limiting position. Inpractice this limit of movement is considerably smallerbecause theaccuracy of the adjustment diminishes rapidly as the follower approachesthe 90 angle. It frequently occurs,

however, that there is need for adjustments of 90 and more in thecase'of various mechanisms, as for instance, where a chuck is carried bya turntable, and in the course of the rotation'of the turntable it isdesired to swing the chuck to various operating positions. Such acondition arises for example, in the case of machines for grindinghypodermic needles where the needle point must be ground from severalwidely divergent angles, necessitating adjustment of the chuck throughlarge angles.

Thecam adjustment of a member such as a chuck on a rotating table is thesimplest and the most efiicient, and therefore this invention seekstoretain this fundamental control of'adjustment' while at the same timepermitting an amplification or multiplication of the movement of the camfollower.

Further objects and advantages of this invention will become apparentin'the following detailed description thereof:

In the accompanying drawings,

Fig. 1 is aperspective view showing the elements comprising thisinvention.

Fig. 2 is a simplified diagram illustrating the theory of the invention.

Fig. 3 is a diagrammatic representation of the Fig. ldevice.

Referring to thedrawings, it will be observed that my invention isillustrated mainly diagrammatically, and therefore no attempt has beenmade to illustrate the ordinary well known machine elements out of whichthe invention would ordinarily be constructed.

A turntable I U'operating around a given center of "rotation movesrelative to a stationary cam II. The. turntable carries a member I2rotat ably mounted thereon about an axis I3. The member I2 maybe a'chuckor any similar Working device whose" position is designedto be variedone or more times-during a revolution of theturntable I0 foraccomplishing various working operations as stated, forexample, in theintro duction hereto."

Normally the adjustment of the rotatable member I2 to the variouspositions would be achieved by fixing to the axis I3 of the chuck I2 acam follower in the form of a crank I5 carry-- ing a roller I6 designedto follow the contour of the cam I I. As the roller I6 moved along theface of the cam II, the crank I5 would be swung around axis I3-to swingthe rotatablemember I2 around said axis to the various positions.however, would give only the same angular movement to member l2 as isimparted to crank I5 by the cam, and as stated,- such movements have atheoretical limit of 99 and an even lesser practical limit; A

' In order that the rotatable member I2 may be rotated through angleslarger than angular movement of cam follower I5 I have provided thefollowing amplification or multiplicationmechanism between the camfollower and the rotatable member I2. For this" purpose the cam followerI5 is not fixed to the axis I3 of rotat-' able member I2, but is merelyloosely mounted for rotation about said axis, and provision is madewhereby when the cam follower I5 is swung through a linear distancecorresponding to a For this purpose an "additional member 20 is carriedby and rotatably, supported in the cam follower I5 in meshing engagementwith member The member 20' is not connected to table- I2. I I), but hasmovement of. translation along an arc 2| and also is capable of rotatingaround its own axis 22. around axis I3 it swings the axis 22 and therotatable member 20 along the are 2 I. The rotat-' able member 20 isgeared to'rotatab-le member I2 either frictionally or by teeth, so thatwhen cam follower I5 is swungaround axisl3 it will swing' rotatablemember 20 around axis I3, and by reason of the geared relation-betweenmember 20 and member I2 it will also swing member I2 around axis I3through the same angular dis tance. Movement of the cam follower I5,therefore, through a predetermined angular distance,

This

As the cam follower I5 rotateswill swing gears 20 and I2 as a unitaround axis I3.

This however accomplishes merely the exact reproduction of angularmovement by rotatable member I2 of the angular movement of the camfollower I5, and the object is to give the rotatable member I2 amultiplied or amplified angular movement in response to the angularmovement of cam follower If). Therefore I have provided means whichbecomes effective just as soon as cam follower I" starts to move gear 20linearly to cause said cam 20 also to rotate around its axis 22, and insuch direction as to cause rotatable member I2 to move further in thesame direction as the linear movement of cam follower I5 caused it tomove. if the cam follower moves from position I in. Fig. 3 to positionII, gears 20 and I2 have also been moved as a unit clockwise through thesame angular distance'as the cam follower. But means are providedwhereby in addition to this movement the gear I2 is further moved in thesame clockwise direction to yield a multiplied or amplified distancerelative to the distance through which the cam follower I5 has moved.

, To accomplish the above, I cause the gear 20 to be set into rotationin a direction opposite to the direction of movement of the cam followerI5 so that the gear I2 will be set into rotation in the same directionasthe movement of cam follower I5; This is accomplished by means of aprojection 40 extending diametrically across the surface of gear 20 andprojecting upwardly from the plane of the paper. The projection 40 abutsagainst a biasing member 4| pivoted about an axis 42 on table III. Axis42 is laterally displaced from axes I3 and 22 and normally pressed'by asource of power, such as coil spring 43, in a direction to cause thebiasing member to abut against the projection 40 in such manner as toexert no torque thereon. It will be seen that when, for instance, thecam follower moves clockwise from position'Itoposition II, theprojection 40 would also tend to move clockwise. This tends to displacethe projection with respect to the biasing member 4| so that instead ofsaid projection and biasingmember being in alignment, they are now outof alignment so that the biasing member engages the lowerv endof theprojection and tends toturnthe projection 40, and hence the gear 20,counter-clockwise until the projection 4|! is again in alignment with:the biasing member 4|. In position II it will be seen by the dash linesthat the member .20 has been rotated counter-clock-- wise through theangle a. This means that the gear I2, inaddition to being rotatedthrough the angle sis also rotated through the angle a and in aclockwise direction, that is, through the same direction asthe movementof the cam follower. Thus, whenthe cam follower moves from position I toposition II, instead of the member I2 being moved only through the angle,3, it is moved through the angle on plus {3 to give a multipliedmovement of the member I2. 7

The movement to the right of the central position shown in Fig. 1operates similarly as the cam follower moves from position I to positionIII, that is, counter-clockwise to move member I2 counter-clockwise. Itwill be seen that in this position the biasing member 4| has moved theprojection 40, and hence the gear 20 clockwise, and hence moved memberI2 counter-clockwise to-add the two movements in the same direction.

The diagram in Fig. -2 gives a simplified illus- Thus, for instance,

tration of the theory of the invention. Thus, if the cam follower movesfrom position I to position III counter-clockwise through the angle 5,the rotatable element I2 would ordinarily also be rotated through theangle 3 because elements 20, I2 and I5 move as a unit around the axisI3. However, in moving from position I to position III, the projection40 on member 20 has also tended to rotate in a counter-clockwisedirection, but this has been prevented by the biasing member 4|, whichcauses the projection to be turned through the angle a, in a clockwisedirection. This causes rotation of gear 20 in a clockwise directionthrough angle a, which causes rotation of gear I2 in a counter-clockwisedirection through the angle 0:, and hence gear I2 has been moved througha total of a plus 5, whereas the cam follower has been moved onlythrough the angle ,3. By moving the pivot 42 nearer to or further frompivot 22 and pivot I3, a greater or lesser multiplication may beobtained. Thus, as 42 is moved to position 42' nearer to pivots 22 andI3, the multiplication increases as shown by the dashline, while if thepivot 42 is moved to position 42" further away from the pivots I3 and 22the multiplication decreases as shown by the dot and dash line.

In accordance with the provisions of the patent statutes, I have hereindescribed the principle and operation of my invention, together with theapparatus which I'now-consider to represent the 1. In a. device of theclass described, a member mounted for rotation about its axis, anoperating'element, means for actuating said element, and means wherebymovement of said element through an angular distance rotates said memberthrough a multiple of said distance, said last named means comprising asecond rotatable member geared to said first member and having its axisdisplaced laterally-with respect thereto, said second member beingmounted for movement of both translation and rotation, means wherebymovement of said element through an angular distance; moves said secondmember linearly through said distance to rotate said first memberthrough said distance, and a source of power independent of saidactuating means and adapted to be rendered effective when said secondmember moves linearly for rotating said second member about its axis torotate said first member.

2. In a device of the class described, a member mounted for rotationabout its axis, an operating element, means for actuating said element,and means whereby movement of said element through an angular distancerotates said member through a multiple of said distance, said last namedmeans comprising a second rotatable whereby movement of said elementthrough an' angular distance moves said second member,

233583595 linearly through said distance .to l rotate. saidstfirst:

member about its axis through said distance in a given direction, and asource of power independent of said actuating means and adapted: to be.rendered'efiective when said second memberisimoved linearly forrotating said second memher. about itsv axis in such. direction thatsaid first. member is rotated further about its axis in. said ivendirection. 7

3. In a device of the class described, a member through an: angulardistance rotates said member through a multiple of said distance, saidlast named means comprising a second rotatable membergeared to saidfirst member and having its axis displaced laterally with respectthereto, said second member being mounted for movement'ofbothtranslation and rotation, means whereby movement of said element throughan angular distance moves said second member linearly through saiddistance to rotate said first member about its axis through saiddistance in a given direction, and a source of power independent of saidactuating means and adapted to be rendered effective when said secondmember is moved linearly for rotating said second member about its axisin a direction opposite to said given direction whereby said firstmember is rotated further about its axis in said given direction.

4. In a device of the class described, a member mounted for rotationabout its axis, an operating element movable about said axis, and meanswhereby movement of said element through an angular distance rotatessaid member through a multiple of said distance, said last named meanscomprising a second rotatable member geared to said first member andhaving its axis displaced laterally with respect thereto, said secondmember being mounted for movement of both translation and rotation, aconnection between said element and said second member whereby movementof said element through an angular distance moves said second memberlinearly through said distance to rotate said first member about itsaxis through said distance in a given direction, and means renderedefiective when said second member is moved linearly for rotating saidsecond member about its axis in a direction opposite to said givendirection of movement of said first member, whereby said first member isrotated further about its axis in said given direction, said last namedmeans comprising a projection carried by said second member, a biasingdevice mounted for movement about a fixed axis laterally displaced fromthe axis of said members, and a source of power for causing saidprojection to maintain a fixed angular relationship with respect to saiddevice.

5. In a device of the class described, a member mounted for rotationabout its axis, an operating element movable about said axis. and meanswhereby movement of said element through an angular distance rotatessaid member through a multiple of said distance, said last named meanscomprising a second rotatable member geared to said first member andhaving its axis displaced laterally with respect thereto, said secondmember being mounted fo movement Of both translation and rotation, aconnection between said element and said second member whereby movementof said element through an angular distance moves said second memberlinearly through said distance to rotate said first member about itsax-is throughsaid distance in a given direction, and means renderedeffective when said second member is moved linearly for rotating saidsecindependent of the 0nd member: about its axis in a direction oppositeto said given direction-of movement of said first member, wherebysaidfirst member is-rotated further. about its axis in said givendirection, said last named means comprising a projection carried by saidsecond gear along a diam"- eter thereof, albiasing device mounted formovement about a fixed axis laterally displaced from theaXis ofsaidmembers, and a source of power for causing said projection tomaintain a fixed angular relations ip with respect to said device.

6; Insa device of the class described, a turntable rotatable about itsaxis, said turntable having a member rotatably mounted thereon, anoperating element carried by said turntable, a fixed cam'with'which'saidelement cooperates to'move saidel'ement' through predetermined angulardistances as said turntable rotates relative to said cam, and meanswhereby movement of said element through a predetermined angulardistance rotates said member through a multiple of said distance, saidlast named means comprising a second rotatable member geared to saidfirst member and having its axis laterally displaced with respectthereto, said second member being movable with said turntable andmounted for both translation and rotation, means whereby movement ofsaid element through an angular distance moves said second memberlinearly through said distance to rotate said first member linearlythrough said distance to rotate said first member about its axis throughsaid distance in a given direction, and means rendered eiTective whensaid second member is moved linearly for rotating said second memberabout its axis in a direction opposite to said given direction ofmovement of said first member, whereby said first member is rotatedfurther about its axis in said given direction. I

7. In a device of the class described, a turntable, a cam, saidturntable and said cam being relatively movable, a member mounted onsaid turntable for rotation about the axis of the mem- 1 erally withrespect thereto, said second member being rotatably mounted on saidfollower whereby movement of said follower through an angular distancemoves said second member linearly through said distance to rotate saidfirst member through said distance, and a source of power means whichactuates said follower and adapted to be rendered effective when saidsecond member moves linearly for ro-y tating said second member aboutits axis to rotate said first member.

8. In'a device of the class described, a turntable, a cam, saidturntable and said cam being relatively movable, a member mounted onsaid turntable for rotation about the axis of the member, a cam followerpivotally mounted at one end on said turntable for'movement about theaxis gagement with the cam, and meanswhereby movement of said followerthrough an angular distance rotates said member through a multiple ofsaid distance, said last-named means comprising a second rotatablemember geared to said first member and having its axis displacedlaterally with respect thereto, said second member being rotatablymounted on said follower whereby movement of said follower through anangular distance moves said second member linearly through said distanceto rotate said first member through said distance, and a source of powerindependent of the means which actuates said follower and adapted to berendered effective when said second member moves linearly for rotatingsaid second member about its axis in such direction that said firstmember is rotated further about its axis in said given direction.

9. In a device of the class described,a turntable, a cam, said turntableand said cam being relatively movable, a member mountedon said turntablefor rotation about the axis of the member, a cam follower pivotallymounted at one end on said turntable 'for movement about the axis ofsaid member and having its other end in engagement with the cam, andmeans whereby,

of said distance, said last-named means comprising a second rotatablemember geared to said first member and having its axis displaced laterally with respect thereto, said second member being rotatably mountedon said follower whereby movement of said follower through an angulardistance moves said second member linearly through said distance torotate said first mem ber. through said distance, and a source of powerindependent of the means which actuates said follower and adapted to berendered effective when said second member moves linearly for rotatingsaid second member about its axis in a direction opposite to said givendirection whereby said first member is rotated further about its axis insaid given direction.

7 r LEO ROBBINS.

